On this point, am I wrong in thinking that drums are deliberately tuned so that they don't boom at any "normal" pitch? One exception might be tablas.
Tony ----- Original Message ----- From: "Eric Liefeld" <[EMAIL PROTECTED]> To: "guy_and_liz Smith" <[EMAIL PROTECTED]> Cc: "Ed Durbrow" <[EMAIL PROTECTED]>; "lute list" <[EMAIL PROTECTED]> Sent: Sunday, January 18, 2004 11:46 PM Subject: Re: Electronic tuners > I agree with Guy that one certainly wouldn't want an instrument to > resonate loudly at one particular frequency (and not so much at others). > And there is certainly more involved in sound production than the RF > of the chamber (and I'm certainly no Physicist). > > That said, I went through a couple of my mandolinos that are > supposedly close copies of real instruments. From what I can tell, > the copy of the tiny Cutler-Challen Strad has an RF pitched at "a" > while a somewhat larger early-18th-century model has an RF a fourth > lower at "e" (A-415 reference pitch for both). These are two very > different instruments with one being at least 1/3 larger in body > volume. > > I find it intesting that both "a" and "e" are open (and often-used) > strings in the middle range of the instrument (where it seems to need > the most support for good tone production). These tiny instruments > need all the vibrational help that they can get and "tuning the instrument > to itself" so that at least one course sits near the natural RF seems to > help. > > Eric > (man of anti-gravitas :-)) > > ps - Here's a page that explains cavity frequencies. To find the volume > of your lute, just fill it with water and then pour out it into a > measuring > container of some sort ( :-) :-) :-) ... ): > > http://hyperphysics.phy-astr.gsu.edu/hbase/waves/cavity.html#c1 > > guy_and_liz Smith wrote: > > >You really wouldn't want an instrument to be strongly resonant at a > >particular frequency. I think that they did at least some things to > >distribute the frequency response over a wide range. Something I picked up > >from Grant Tomlinson's class this summer: in theory, the braces under the > >top are perpendicular to the centerline and evenly spaced. That degree of > >symmetry would tend to favor the fundamental vibration modes of the top. In > >actual practice (from Grant's extensive study of historical lutes), the > >braces on historical instruments depart somewhat from both regular spacing > >and perpendicularity. From what I understand of acoustics, this should serve > >to spread out the frequency response of the top, and make it less responsive > >to any particular frequency and more uniform over the whole range of > >frequencies (the other physicists can chime in if they have a better > >understanding of this issue). > > > >FWIW, I'm a little puzzled by the emphasis on the resonant frequency of the > >interior of the instrument. I rather suspect that such a resonance is at > >most a secondary factor, the primary one being the elastic properties of the > >top. If it was mainly about the geometry of the bowl, I doubt that luthiers > >would spend so much money on tonewood, nor would they go through the sort of > >elaborate tuning process that Bob Lundberg describes in his book. > > > >Guy > > > > > >----- Original Message ----- > >From: "Eric Liefeld" <[EMAIL PROTECTED]> > >To: "Ed Durbrow" <[EMAIL PROTECTED]> > >Cc: "lute list" <[EMAIL PROTECTED]> > >Sent: Sunday, January 18, 2004 12:34 PM > >Subject: Re: Electronic tuners > > > > > > > > > >>Hi Ed, > >> > >>My understanding is that the resonant frequency of a volume (such as a > >>lute or guitar) is a function of both the volume, and the size of the > >>sound > >>hole. So yes, in theory, a luthier could adjust the frequency somewhat > >>by varying the size of the rose... though all the frilly bits might make > >>this > >>a bit tough to do predictably. > >> > >> From a practical perspective, I'd be interested in knowing if any > >>luthiers > >>actually do this "tuning". > >> > >>Eric > >> > >> > >> > >>>James, > >>> This is amazing. I tried this on my Baroque guitar. I merely muted > >>>the strings with my hand. It clearly resonates at d and f. This is > >>>good, I like Dm. :-) On my Ren lutes, it wasn't as pronounced and > >>>seemed to be a wider Q factor (width). My B lute resonates at A low > >>>pitch. This is truly facinating. > >>> > >>> > >>> > >>> > >>> > >>>>The difference is amazing. If you're not the sort to be convinced, > >>>>as I am, by the physics, the sound will decide it--as it should. > >>>>The resonance of the instrument will be greatly magnified, as will > >>>>the volume, and even the clarity of the plucked notes and their > >>>>overtones. I have done it with two 64cm lutes, one responded at E > >>>>and the other at F. They are much the richer for it--totally > >>>>different instruments. They stand up very well to a voice they > >>>>accompany, without being overwhelmed. The harmonic synergy between > >>>>the voice and lute (if it's you singing) is palpable. > >>>> > >>>> > >>>> > >>>> > >>>I'm wondering if this is something easy or difficult for a luther to > >>>control. Do they design instruments to resonate at certain pitches? > >>>If there is too much resonance doesn't that give an uneven response? > >>>Who wants to be trying to play something evenly and one note suddenly > >>>jump out? I haven't noticed that problem on my B guitar, but it is > >>>pretty much a tank of an instrument anyway. > >>> > >>> > >>> > >>> > >> > >> > >> > >> > > > > > > > > > > > >
